Age-related Macular Degeneration, or AMD, is a disease that mainly affects people over 65 years of age. It is the result of “aging” of the macula, the most sensitive area of the retina. There are two forms of AMD: “dry” and “wet”. Although it affects fewer patients, “wet” AMD is responsible for most cases of AMD-related blindness. In situations of “wet” AMD, abnormal blood vessels (neovascularization) appear, which eventually burst and cause haemorrhages and scarring in the back of the eye.
What are the symptoms of AMD?
Dark or whitish mark in the center of the field of vision, distorted images, blurring, or changes in size or shape of objects. Because the central vision is affected, the patient has difficulty reading and writing, recognizing faces, watching television, etc. In most cases, AMD eventually affects both eyes, over a period of time ranging from a few months to several years.
What is the treatment?
The retina destroyed by AMD cannot be recovered, and the loss of vision is permanent. However, there are treatments that can either halt or delay its progression, depending on the type of AMD, which may be “dry” or “wet”. The “dry” form of AMD is not treatable, but vitamin and anti-oxidant therapies can be given that appear to decrease the risk of progression to the advanced forms of the disease. For the “wet” form of AMD, treatment is available, and this should be started as early as possible.
Prior to the year 2000, the only treatment available for “wet” type AMD was laser. However, this could only treat a small number of patients who had lesions in the fundus of the eye with well defined characteristics. It was also a destructive treatment that aimed to destroy the neovessels but simultaneously causing burning of the retina, which in itself led to severe visual loss.
Photodynamic therapy with verteporfin (Visudyne ®) appeared in 2000, as the first selective treatment that enabled the neovessels to be destroyed while preserving much of the adjacent retina. However, it could not treat all types of lesion that appear in clinical practice, and despite the treatment, patients’ vision tended to continue to decline, albeit to a lesser extent than in untreated patients.
In 2004, new treatments with intravitreal injection of antiangiogenic drugs began to emerge. This involves injecting medications into the eyeball that inhibit the growth of the anomalous vessels. When performed by trained ophthalmologists and under aseptic conditions, it is a relatively painless and safe procedure. This new treatment provides hope for patients with macular lesions that, up until now, were considered untreatable. Since the available treatments do not guarantee a cure, it is very important to control the disease, and to be aware of the evolution of the lesions. For this reason, the ophthalmologist may advise the patient to perform a simple vision test each day, using the Amsler grid.